Polyamide containing recurring saturated fluorene rings



United States Patent 3,468,850 POLYAMIDE CONTAINING RECURRING SATURATEDFLUORENE RINGS Peter William Foster, Geneva, Switzerland, assignor to E.I. du Pont de Nemours and Company, Wilmington, Del., a corporation ofDelaware N0 Drawing. Filed May 20, 1965, Ser. No. 457,504

Int. Cl. C08g 20/00 US. Cl. 260-78 1 Claim ABSTRACT OF THE DISCLOSURE Asynthetic linear fiber-forming polymer consisting essentially ofrecurring units of the formula wherein the geometric figure containingthe letters S denotes a saturated fluorene ring for the hydrogen ofwhich R, representing alkyl containing no more than 3 carbon atoms, maybe substituted, and wherein n is a whole number from 0 to 12, inclusive,preferably a number from 4 to inclusive. The polymer may contain up to10 weight percent of polyamide copolymeric units.

This invention concerns a novel and useful polymer. More specifically,it relates to a synthetic, linear, fiberforming polyamide containingpolyalicyclic groups as an integral part of the polymer chain.

An object of this invention is to provide a novel and usefulfiber-forming polymer. Another object is to provide a novel and usefulfiber-forming polymer having good resilience. Still another object is toprovide a synthetic linear fiber-forming polycarbonamide containingfused alicyclic groups as an integral part of the polymer molecule.These and other objects will become apparent in the followingspecification and claims.

In accordance with the present invention a synthetic linear,fiber-forming polymer is provided consisting essentially of recurringunits of the Formula I wherein the geometric figure containing theletters S denotes a saturated fluorene ring for the hydrogen of which R,representing alkyl containing no more than 3 carbon atoms, may besubstituted, n equals a whole number from 0 to 12 inclusive butpreferably 4 to 10 inclusive, and X is copolymeric units wheneverpresent constituting no more than about 10 mol percentage of the saidpolymer and being a member of the class consisting of polyamides,polyesters, polyurethane, polysulfonamide and polyureas.

The radical may be linked to any of the 4 carbon atoms of the 6 memberedrings which are not involved in the fused ring linkages, provided theyare not on the same ring. Preferably the two X radicals are attached tothe perhydrofiuorene nucleus in a symmetrical manner.

A preferred embodiment of the invention is a synthetic, linear,fiber-forming polycarbonamide wherein the recurring carbonamide linkageis an integral part of the Patented Sept. 23, 1969 polymer chainconsisting essentially of recurring units of the Formula II OH H! Byfiber-forming is meant that the product of this invention is capable ofbeing formed into useful filaments and fibers. The fiber-forming stagecan be tested for in the conventional manner by touching the moltenpolymer with a rod and drawing the rod away. A continuous filament ofconsiderable strength and pliability is readily formed if afiber-forming stage has been reached. Normally a sufficiently highmolecular weight to provide an inherent viscosity of at least 0.4 isrequired to reach the fiber-forming stage. Inherent viscosity asdiscussed herein is determined in a conventional manner on a solutioncontaining .25 gram of polymer in 50 milliliters of m-cresol.

The polymers of this invention can be prepared in a conventional mannerfrom the diamines or their amide forming derivatives and thedicarboxylic acids or their amide forming derivatives. The alicyclicdiamines used as starting materials can be prepared using conventionalorganic synthetic procedures by nitrating fluorene to form the dinitrocompound, followed by hydrogenation of both the nitro groups and thearomatic rings to produce the diaminoperhydrofiuorene compound.Conventional techniques can be used to separate the resulting isomers asdesired. Perhydrofluorene dicarboxylic acid compounds may be preparedusing conventional organic synthesis techniques by reduction of thecorresponding dinitrofluorene compound to the aromatic diamine. Thediamine is then converted to the aromatic dinitrile, by a Sandmeyerreaction for example, and hydrolyzed to the aromatic diacid. Thefluorene dicarboxylic acid is then hydrogenated to give thecorresponding dicarboxylic perhydrofluorene.

The following examples are cited for description purposes only and arenot intended to limit the scope of the invention. Tensile strainrecovery as reported herein is useful for predicting wash-wearperformance. It is conducted by mounting a 10 in. specimen in the yarnclamps of an Instron Tensile Tester, immersing the specimen in 40 C.water for 2 minutes and then extending to a given elongation (0.5, 1.0,1.5, 2.0, 3.0%). The clamp separation is maintained for a 2 minuteperiod. The immersion tank is removed from the specimen and the stressreduced to 0.042 g.p.d., and maintained for a 2 minute period. TheInstron clamps are then returned to the original separation and theresulting increase in yarn slack measured. The dilference between theamount of elongation imparted to the yarn and the amount of slackremaining after recovery is an indication of the recovery obtained atspecific elongations. The test is repeated with a fresh sample at eachelongation. The tensile strain recovery value is plotted vs. elongationand the area under the curve integrated; this indicates the averagevalue at 0.042 g.p.d. stress. The final value recorded is the average ofthe determinations at the five different elongations. The stress levelof 0.042 g.p.d. is chosen to simulate the effect of fiber friction in afabric. A tensile strain recovery value of 40 or above is considered togive acceptable wash-wear performance.

EXAMPLE I 2,7-diaminofluorene grams) is hydrogenated in 100 ml. dioxaneusing 10 grams 5% ruthenium on aluminum oxide as catalyst in thepresence of 25 grams ammonia at 200-215 C., and 5,000 p.s.i. hydrogenpressure. The resulting 2,7-diaminoperhydrofiuorene has a boiling point161 C./ mm. mercury and a neutralization equivalent of 113. Vapor phasechromatography of the N,N'-diethyl derivatives shows the presence of 4geometrical isomers (17, 18, 60 and 5% composition).

Thirty-three grams 2,7-diaminoperhydrofluorene are added to 23.2 gramsadipic acid heated in 84 ml. water. A nylon salt is formed in solutionand the pH is adjusted to 7.7 by addition of2,7-diaminoperhydrofiuorene. On evaporation 45 grams of the ammoniumsalt are obtained.

The salt is charged in a glass polymer tube, the tube purged withnitrogen, evacuated and sealed off and thereafter heated for 2 hours at235 C. After this, the tube is opened and heated under nitrogen for 2hours at 300 C. The resulting polymer has an inherent viscosity of 0.64and a polymer softening temperature, as determined on a heated metalblock, of 260-265 C.

Filaments are prepared by press Spinning molten polymer at 3l0-330 C.with a windup speed of 150-300 ft. per minute using a plunger pressureof 400 p.s.i. The quench filaments are drawn 2.75 X over an 80 C.,heated pin. The drawn fibers are heated in water at 70 C., and, afterair drying, physical properties as shown in the following table arefound:

Tenacity1 .3 grams per denier Elongation3 8 Initial modulus-28 Workrecovery, 3 S %--74/ 61 Tensile recovery, 3 5 %-90/ 89 Tensile strainrecovery-46 Work recovery and tensile recovery values are shown at both3 and 5% elongations.

EXAMPLE II A diammoniurn salt is prepared by adding 10.7 grams2,7-diaminoperhydrofiuorene in 25 ml. isopropanol to 9.4 grams azelaicacid in 80 ml. isopropanol. The salt separates as an oil and solidifiesupon standing. Yield is 8 grams. The pH of the 1% solution is 5.7 and apH of 7.75 is found at the isoelectric point. Using the procedure ofExample I, the salt is heated in a sealed tube at 235 C. for two hours,then under nitrogen for 2 hours at the same temperature. The resultingpolymer has an inherent viscosity of 0.73 and a polymer softeningtemperature of 175-180 C.

EXAMPLE III A solution of 42.5 g. of 2,7-diaminoperhydrofluorene in 100cc. of ethanol is added to 46 g. of dodecanedioic acid dissolved in 300cc. of ethanol. The salt crystallizes after cooling on standing. Theyield is 75 g. The pH of a 0.5% solution in water is 7.2 and the pH atthe isoelectric point is found to be 7.75. Using the procedure ofExample I, the salt is heated in a sealed tube at 235 C. The resultingpolymer has an inherent viscosity of 0.76 and a polymer softeningtemperature of 170-175 C.

This invention includes polycarbonamides which can be prepared from anyperhydrofiuorene diamine or any dicarboxylic acid in which the tworeactive groups are not attached to the same 6 membered ring. Referringto Formula III,

the functional groups may be attached to the perhydrofiuorene nucleus inany of the positions 1 through 8 inclusive. Preferred constituents arethose substituted in a symmetrical manner such as 1,8-diamino-;2,7-diamino-; 3,6-diamino-; and 4,idiaminoperhydrofluorene and thecorresponding dicarboxylic acids. Unsymmetrically substituted compoundssuch as 1,5-diamino-; 2,6-diamino-; 3,8-dicarboxy-perhydrofiuorene andthe like are also suitable.

The polymers of this invention contain in addition to perhydrofiuorenenuclei, straight chain alkylene groups. When the polymer is based ondiaminoperhydrofluorene units, the aliphatic units are derived fromalpha,ornegaaliphatic dicarboxylic acids. Examples of such acids areoxalic, adipic, azelaic, sebacic, and the like. When the polymer isderived from a perhydrofiuorene dicarboxylic acid, the aliphaticstraight chain hydrocarbon units are derived from aliphatic diaminessuch as ethylene diamine, hexamethylene diamine, nonamethylene diamine,decamethylene diamine and the like.

The polymers of this invention may also contain copolymeric units aspreviously recited. Examples of such copolymeric polyamide units arehexamethylene adipamide, hexamethylene sebacamide, metaphenyleneisophthalamide, hexamethylene terephethalamide, caproamide, and thelike.

The di-substituted perhydrofluorene compounds of this invention exist invarious geometrical isomer forms. The' geometrical isomer compositioncan be regulated by known isomer purification techniques and by theexperimental conditions employed for hydrogenation of the aromaticrings. The geometrical isomer composition determines somewhat theproperties of the polymers and fibers prepared therefrom.

The polymers, filaments, and fibers of this invention are useful intextiles, knitted and nonwoven fabric applications and other well-knownuses for synthetic polymers, filaments and fibers.

The polymer may be used as a homopolymer, or blended or cospun withother polymers by procedures well known in the art. They may containconventional additives such as stabilizers, antioxidants, delusterants,pigments, dyes, antistatic agents and the like.

Other aspects of the invention will be obvious to those skilled in theart. The invention is limited only as defined by the following claim.

What is claimed is:

1. A synthetic, linear, fiber-forming polycarbonamide consistingessentially of recurring units of the formula wherein the geometricfigure containing the letters S denote a perhydrofiuorene ring in whichR may be hydrogen or an alkyl radical containing no more than 3 carbonatoms, and n is a whole number from 0 to 12 inclusive.

References Cited UNITED STATES PATENTS 2,585,163 2/1952 Pease et al.260-78 3,069,468 12/1962 Cox et al. 26078 3,143,530 8/1964 DOIlOfriO260-78 HAROLD D. ANDERSON, Primary Examiner US. Cl. X.R.

